Dowel device with closed end speed cover

ABSTRACT

Disclosed are a concrete dowel placement devices and a method of utilizing the same. A metallic stud is driven, screwed, or otherwise attached to a form. The stud may be a unitary structure, or may be a hollow tube with conventional fastening means such as nails and screws extending through and holding the hollow tube to the form. A cover having an interior compartment substantially equal in diameter to the stud is slidably placed thereon, and a first enclosed area is developed with a plurality of forms. Concrete is poured into the first enclosed area, and upon curing, the form and the stud are removed, leaving the cover embedded in the concrete. A metallic dowel is inserted into the cover, and a second enclosed area is developed with like configured forms. The metallic dowel extends into the second enclosed area. Upon pouring concrete into the second enclosed area, a cold joint is formed between the concrete of the first enclosed area and the concrete of the second enclosed area, supported and braced by the metallic dowel.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT

Not Applicable

BACKGROUND

1. Technical Field

The present invention relates generally to the art of concreteconstruction. More particularly, the present invention relates to anapparatus for facilitating the placement of slip dowel rods withinadjacent concrete slabs.

2. Related Art

In the concrete construction arts, “cold joints” between two or morepoured concrete slabs are frequently used for the paving of sidewalks,driveways, roads, and flooring in buildings. Such cold joints frequentlybecome uneven or buckled due to normal thermal expansion and contractionof the concrete and/or compaction of the aggregate caused by inadequatepreparation prior to pouring of concrete. As a means of preventingbucking or angular displacement of such cold joints, it is commonpractice to insert smooth steel dowel rods generally known as “slipdowels” within the edge portions of adjoining concrete slabs in such amatter that the concrete slabs may slide freely along one or more of theslip dowels, permitting linear expansion and contraction of the slabswhile also maintaining the slabs in a common plane and thus preventingundesirable bucking or unevenness of the cold joint.

In order to function effectively, slip dowels must be accuratelypositioned parallel within the adjoining concrete slabs. Thenon-parallel positioning of the dowels will prevent the desired slippageof the dowels and will defeat the purpose of the “slip dowel”application. Additionally, the individual dowels must be placed withinone or both of the slabs in such a manner as to permit continualslippage or movement of the dowels within the cured concrete slab(s).

A number of methods of installing smooth slip dowels are popular.According to one method, a first concrete pour is made within apre-existing form. After the first pour has cured, and edge of the form,usually a wooden stud, is stripped away. A series of holes are thendrilled parallel into the first pour along the exposed edge from whichthe form has been removed. The depth and diameter of the individualholes varies depending on the application and the relative size of theconcrete slabs to be supported. As a general rule, however, such holesare at least twelve inches deep and typically have a diameter ofapproximately five-eighths (⅝) of an inch.

After the parallel series of holes have been drilled into the firstpour, smooth dowel rods are advanced into each hole such that one end ofeach dowel rod is positioned within the first pour and the remainder ofeach dowel rod is positioned within the first pour and the remainder ofeach dowel rod extends into an adjacent area where a second slab ofconcrete is to be poured. Thereafter, concrete is poured into suchadjacent area and is permitted to set with the parallel aligned dowelsextending thereto. After the second pour has cured, the slip dowels willbe held firmly within the second slab, but will be permitted to slidelongitudinally within the drilled holes of the first slab therebyaccommodating longitudinal expansion and contraction of the two slabswhile at the same time preventing buckling or angular movementtherebetween.

Although the above-described “drilling method” of placing slip dowels ispopular, it will be appreciated that such method is extremely laborintensive. In fact, it takes approximately ten minutes to drill a fiveeighths inch (⅝″) diameter by twelve inch long hole into the first pourand the drilling equipment, bits, accessories, and associated set uptime tends to be very expensive. Moreover, the laborers who drill theholes and place the slip dowels must be adequately trained to ensurethat the dowels are arranged perpendicular to the joint but parallel toone another so as to permit the desired slippage.

Another popular method of placing slip dowels involves the use ofwax-treated cardboard sleeves positioned over one end of each individualdowel. According to such method, a series of holes are drilled throughone edge of the concrete form and smooth dowels are advanced througheach such hole. Thereafter, the treated cardboard sleeves are placedover one end of each dowel, with a first pour subsequently being madewithin the form which covers the ends of the dowels including thecardboard sleeves thereon. After the first pour has set, the previouslydrilled form is stripped away, leaving the individual dowels extendinginto a neighboring open space where the second pour is to be made.Subsequently, the second pour is made and cured. Thereafter, the slipdowels will be firmly held by the concrete of the second pour, but willbe permitted to longitudinally slide against the inner surfaces of thewax treated cardboard sleeves within the first pour. Thus, the waxedcardboard sleeves facilitate longitudinal slippage of the dowels, whileat the same time holding the two concrete slabs in a common plane, andpreventing undesirable buckling or angular movement thereof.

This method was also associated with numerous deficiencies, namely, thatafter the first pour was made, the free ends of the dowels were likelyto project as much as eighteen inches through the form and into the openspace allowed for the second pour. Because the drilled section of theform must be advanced over those exposed sections of dowel to accomplishstripping or removal of the form, it is not infrequent for the exposedportions of the dowels to become bent and, thus, non-parallel.Additionally, the drilled section of the form became damaged or brokenduring the removal process, thereby precluding its reuse.

Each of the above described known methods of placing slip dowels betweenconcrete slabs often results in the dowels being finally positioned atvarious angles rather than in the desired parallel array. Therefore, thenecessary slippage of the dowels is impeded or prevented.

In response to such deficiencies in the art, a number of dowel placementsleeves have been developed. One such development is U.S. Pat. No.5,005,331 to Shaw, et al., which is wholly incorporated by referenceherein, teaches a slip dowel positioning device that is extractable fromthe first concrete slab. The device is comprised of a hollow cylindricalportion with a flange or gusset extending perpendicularly therefrom. Theflange permitted the device to be attached to the form, and upon curing,the form was removed, thereby also removing the positioning device.Thereafter, a smooth dowel was inserted in the cavity formed in thespace previously occupied by the positioning device, and a subsequentslab of concrete was poured. One of the deficiencies associated with the'331 device was that it was required to be removed from a cured slab ofconcrete, necessitating extra force during removal. Further, theconfiguration which enabled the positioning device to be removableresulted in a cavity which was less than ideal, in that slightdiscrepancies in the angular displacement of the smooth dowel areintroduced. Therefore, slip dowel placement which was truly parallel tothe concrete surface is not possible.

Thus, alternatively, the '331 patent and additionally U.S. Pat. No.5,216,862 to Shaw, et al., which is also incorporated by referencewherein, contemplated a positioning device which remained in theconcrete slab. The positioning device was attached to the form viastaples or small nail heads, and forcibly stripped upon curing of thefirst slab of concrete. However, the requirement of forcibly removingthe form from the positioning device remained.

Accordingly there is a need in the art for an inexpensive and readilyreproducible dowel positioning device which can remain in the concreteslab after curing. Further, there is a need for a dowel positioningdevice which can be attached and removed from a form with minimal forceand a minimum number of extraneous components. These needs and more areaccomplished with the present novel and inventive device, the details ofwhich are discussed more fully hereunder.

BRIEF SUMMARY

In light of the foregoing problems and limitations, the presentinvention was conceived. In accordance with one embodiment of thepresent invention, provided is a concrete dowel placement device forattachment to a form. More particularly, the device comprises a studhaving a generally tubular body, a proximal stud end and a distal studend, and a cover having a generally tubular body having an outer coversurface, an open proximal cover end, a closed distal cover end, and ahollow cover interior compartment extending axially therein configuredto slidably receive the stud. In one embodiment, the stud is of uniformconstruction and has a form insertion section disposed towards theproximal stud end and encompassed by the form, and a cover insertionsection disposed towards the distal stud end and encompassed by thecover. The form insertion section extends beyond the proximal cover endwhen the cover is placed on the stud. Furthermore, the form insertionsection is tapered to a point defining the proximal stud end for ease indriving the stud into the form. Alternatively, the form insertionsection is threaded and tapered to a point defined by the proximal studend for screwing the stud into the form. In order to enable the stud tobe screwed into the form, the distal stud end defines a molded surfaceconfigured to cooperate with a screwdriver head.

In accordance with another embodiment of the present invention, thedistal stud end and the proximal stud end each have an opening and ahollow stud interior compartment extending axially therebetween. Thestud is configured to slidably receive a nail having a length greaterthan that of the hollow stud interior compartment, the nail having ahead in an abutting relationship with the distal stud end and a pointdriven into the form. In another embodiment, the stud is configured toreceive a threaded screw having a length greater than that of the hollowstud interior compartment, with the screw having a head in an abuttingrelationship with the distal stud end and a point screwed into the form.Further, the stud may include threading disposed in the hollow studinterior compartment to cooperatively retain the threaded screw.

According to yet another aspect of the present invention, the coverincludes an integrated flange on the proximal cover end. Preferably, thecover is formed of plastic, and the stud is ¼ inch in diameter. Alongthese lines, the hollow stud interior compartment is also ¼ in diameter.

In accordance with still another aspect of the present invention,disclosed is a method for forming a cold joint between adjoiningsequentially formed slabs of concrete. The method is comprised of a)securing one or more studs to one or more forms; b) attaching a cover onto a respective one of the studs; c) forming a first enclosed area withthe forms; d) pouring a first slab of concrete into the first enclosedarea; e) curing the first slab of concrete; f) slidably removing theforms from the slab of concrete thereby concurrently withdrawing thestuds from the covers, wherein the covers remains within the first slabof concrete; g) inserting a dowel into each of the covers remaining inthe first slab of concrete; h) attaching a cover on to respective onesof the studs on the form; i) forming a second enclosed area adjacent tothe first slab of concrete with the forms, wherein at least a part ofthe second enclosed area is defined by an edge of the first concreteslab and at least one of the dowels extend into the second enclosedarea; j) pouring a second slab of concrete into the second enclosedarea; and k) curing the second slab of concrete. The dowel is generallycylindrical, and may be constructed of stainless steel, while the coversare constructed of plastic.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the various embodimentsdisclosed herein will be better understood with respect to the followingdescription and drawings, in which like numbers refer to like partsthroughout, and in which:

FIG. 1 a is a perspective view of a first embodiment of a stud and aspeed cover in accordance with an aspect of the present invention;

FIG. 1 b is a side view of a first embodiment of a speed cover attachedto a stud which is inserted into a form;

FIG. 2 a is an exploded perspective view of a second embodiment of astud having an open distal and proximal ends with a nail to be insertedtherethrough and a speed cover;

FIG. 2 b is a side view of a second embodiment of a speed cover attachedto a stud secured by a conventional nail which is inserted into a form;

FIG. 3 a is an exploded perspective view of a third embodiment of a studhaving an open distal and proximal ends with a screw to be insertedtherethrough and a speed cover;

FIG. 3 b is a side view of a third embodiment of a speed cover attachedto a stud secured by a conventional screw which is inserted into a form;

FIG. 4 is a perspective view of a plurality of forms defining anenclosed area;

FIG. 5 is a perspective view of a first slab of concrete surrounded by aplurality of forms, with one form being removed from the concrete;

FIG. 6 is a perspective view of a first slab of concrete with speedcovers within, and the placement of dowels;

FIG. 7 is a perspective view of a first slab of concrete with speedcovers within and dowels extending into a second enclosed area definedby an edge of the first slab of concrete and a plurality of forms;

FIG. 8 is a perspective view of a first and second slab of concretesupported by a plurality of speed covers and dowels within respectiveconcrete slabs; and

FIG. 9 is a side view of a first and second slab of concrete supportedby a speed cover and a dowel within respective concrete slabs.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of the presently preferredembodiment of the invention, and is not intended to represent the onlyform in which the present invention may be constructed or utilized. Thedescription sets forth the functions and the sequence of steps fordeveloping and operating the invention in connection with theillustrated embodiment. It is to be understood, however, that the sameor equivalent functions and sequences may be accomplished by differentembodiments that are also intended to be encompassed within the spiritand scope of the invention. It is further understood that the use ofrelational terms such as first and second, and the like are used solelyto distinguish one from another entity without necessarily requiring orimplying any actual such relationship or order between such entities.

With reference now to the figures, specifically FIG. 1 a and FIG. 1 b, afirst embodiment of the present inventive dowel device with a closed endspeed cover is shown. A form 30, which by way of example only and not oflimitation, is constructed of wood or any other material well known inthe art capable of rigidly defining an enclosed area, and capable ofreceiving and retaining a fastener such as a stud 20, a nail 140 asillustrated in FIG. 2 a or a screw 240 as illustrated in FIG. 3 a. Stillreferring to FIG. 1 a and FIG. 1 b, according to a first embodiment ofthe present invention, the stud 20 includes a tapered section 26, whichtapers to define a sharp point disposed at a proximal end 24, a shaftportion 28, and a distal end 22. The proximal end 24 is inserted ordriven into the form 30, and is frictionally retained therein. As willbe appreciated by one having ordinary skill in the art, the taperedsection 26 enables the stud 20 to be driven into the form 30 with alesser amount of force. The stud 20 is typically a quarter-inch (¼″) indiameter, and may be constructed of any suitable material such as steel,stainless steel, or other metals having sufficient strength to preventdeformation of the stud 20 upon driving the same into the form 30.

After driving the stud 20 into the form 30, a speed cover 10 is placedon the stud 20, covering the exposed part of a shaft portion 28, i.e.,the portion not encompassed by the form 30. The speed cover 10 isdefined by a tubular body 12, a closed distal end 14, and an openproximal end 16, and includes an interior compartment 18 which extendsaxially from an interior distal end surface 19 through a tubular body 12to the open proximal end 16. The diameter of the interior compartment 18is sufficient to enable a sliding relationship between the speed cover10 and stud 20. While the preferred configuration is for the distal end22 of the stud 20 to be in an abutting relationship with the interiordistal end surface 19, and the open proximal end 16 to be in an abuttingrelationship with the form 30, strict adherence to this configuration isnot necessary. For example, the stud 20 may be inserted further into theform 30, leaving a slight gap between the distal end 22 of the stud 20and the interior distal end surface 19 of the speed cover 10 when it ispositioned on the stud 20. Preferably, though not necessarily, theproximal end 16 additionally defines a flange 11 extending arcuatelyabout the speed cover 10. Further, the speed cover 10 may be integrallyformed of a plastic material fabricated by conventional moldingtechniques.

In a second embodiment shown in FIGS. 2 a and 2 b, a sleeve stud 120 hasan open distal end 123, with an interior compartment 129 extendingtherethrough. An open proximal end 124 is in an abutting relationshipwith the form 30, and a conventional nail 140 having a nail point 143and a nail head 142 is inserted through the interior compartment 129 anddriven through the form 30. The diameter of the interior compartment 129is larger than that of the nail 140, thereby enabling a sliding relationbetween the sleeve stud 120 and the nail 140, while smaller than that ofthe nail head 140 to prevent the sleeve stud 120 from being withdrawnfrom the nail 140 once inserted. The diameter of the sleeve stud 120 istypically quarter-inch (¼″) and may be constructed of metal or othersuitable material. Like the aforementioned first embodiment, the speedcover 10 includes a tubular body 12, an interior compartment 18, aclosed distal end 14, and an open proximal end 16, through which thesleeve stud 120 may be inserted. The proximal end 16 is preferably in anabutting relation to the form 30 once placed on to the stud 120.Additionally, the proximal end 16 may also define the flange 11.

Referring now to FIG. 3 a and 3 b, a third embodiment of the presentinvention is shown, with the sleeve stud 120 having the open proximalend 124, the open distal end 123, and the interior compartment 129extending therebetween. Instead of a nail as in the second embodiment, ascrew 240 having a screw point 243 and a screw head 242 is provided. Thescrew 240 is inserted through the sleeve stud 120, and screwed orthreaded through the form 30. The screw head 242 preferably includesmolding that cooperates with a screwdriver head. Such screw headsinclude standard Phillips heads, flatheads, hexagonal heads, or anyother like configuration well known in the art. Optionally, the screw240 may be integrally formed with the sleeve stud 120 to eliminate themanual step of inserting the screw 240 through the sleeve stud 120. Asin the previously mentioned first and second embodiments, the speedcover 10 has the open proximal end 16, the closed distal end 14, and theinterior compartment 18 which is in a sliding relationship with thesleeve stud 120. Further, the speed cover 10 may be integrally formed ofa molded plastic, and may include the flange 11 extending from the speedcover 10 in an arcuate fashion. In general, it is to be understood thatany fastening mechanism having an elongate structure with a head orother like feature which directly or indirectly cooperates with the stud120 to attach the same to form 30 is understood to be encompassed by thepresent invention.

While reference has been made to the “stud” 20 as in FIGS. 1 a and 1 b,and to the “sleeve stud” 120 as in FIGS. 2 a, 2 b, 3 a, and 3 b, it willbe understood that with regard to the relationship to the speed cover10, both “stud” 20 and “sleeve stud” 120 include an elongate entitywhich interfaces with the interior compartment 18. As used henceforth indescribing the formation of a concrete structure, the two terms may bereadily interchanged. Further, it is also to be understood that thediameter of studs 20 and sleeve stud 120 are substantially the same asthat of a dowel to be used to rigidify the cold joint between a firstpour and a second pour of concrete.

With reference now to FIG. 4, four forms 30 are arranged in aquadrangular configuration, forming a first enclosed area 310. WhileFIG. 4 illustrates a quadrangular configuration, it is to be understoodthat the first enclosed area 310 can be any shape capable of beingformed using conventional techniques well known in the art. As will beappreciated, a desired surface is excavated and a base course 305comprised of larger-sized aggregate is formed prior to forming the firstenclosed area 310.

As set forth above, preferably each of the forms 30, or at least one ofthe forms 30, have the stud 20 centrally attached thereto by any of thedescribed embodiments, including a unitary stud 20 which includes atapered section for insertion into the forms 30, a separate screw/hollowstud combination or the nail/hollow stud combination. The number of thestuds 20 attached varies according to the needs of each application, andthe proper distribution and spacing will be readily determined by aperson having ordinary skill in the art. Further, each of the studs 20have attached thereto the cover 10 as set forth above. As the height ofthe forms 30 defines the height of the ultimate concrete structureformed thereby since concrete is poured to be flush with the uppersurface of the same, preferably the studs 20 are inserted in thelongitudinal center of forms 30 to maximize the compressive strength ofthe concrete. Typically, the forms 30 are dimensional lumber such as atwo-by-four, which is nominally two inches by fourt inches (2″ by 4″),but can be as small as one and a half inches by three and a half inches(1½″ by 3½″).

Still referring to FIG. 4, and now, additionally to FIG. 1 a, uponforming an enclosed area 310 on top of a base course 305 in the desiredconfiguration, a slab of concrete 300 is poured therein. Although anywell known paving material may be used, concrete comprised of Portlandcement and a mineral aggregate such as gravel or sand is preferred. Asis understood, concrete is liquid in form before curing, and afterpouring, the cement begins to hydrate and glue the aggregate and thecement together, forming a rock-like material. Thus, the outer surfaceof the speed cover 10 forms a bond with the surrounding concrete slab300, and remains embedded therein. Since the proximal end 16 of speedcover 10 abuts the form 30, and therefore the edge of the concrete slab300, the interior compartment 18 does not fill with concrete and remainsexposed to the exterior of concrete slab 300. The occupation of theinterior compartment 18 by the stud 20 further reduces the tendency ofconcrete to flow inside speed covers 10.

Now referring to FIG. 5, shown is the first cured slab of concrete 300,with the form 30 being removed. Along with the form 30, also removed arethe studs 20 previously embedded within the speed cover 10. As a resultof the sliding relation, the studs 20 are easily and quickly removedfrom the speed covers 10. As illustrated, the speed covers 10 remains inthe cured slab of concrete 300, and the open proximal end 16 of thespeed covers 10 forms an edge of the cured slab of concrete 300.Further, a cavity within the cured slab of concrete 300 is effectivelydefined by the interior compartment 18 of the speed covers 10.

Referring to FIG. 6, metallic dowels 80 are inserted into the interiorcompartment 18 of each of the speed covers 10 embedded within the firstcured concrete slab 300. Essentially, the speed covers 10 eliminate theerror-prone drilling step in previously known methods of formingcavities for inserting dowels to brace “cold joints” between twosequentially poured slabs of concrete. The metallic dowels arepreferably quarter inch (¼″) in diameter, and constructed of stainlesssteel. As a person of ordinary skill in the art will recognize, asmaller diameter stainless steel dowel possesses the same sheer strengthcharacteristics as that of a larger diameter mild steel dowel. Forexample, a quarter-inch (¼″) stainless steel dowel has the same sheerstrength as that of a half-inch (½″) mild steel dowel. Preferably, themetallic dowels 80 extend fully into speed cover 10, and extend asubstantial distance out of the same.

With reference now to FIG. 7, a second enclosed area 410 is constructedwith the forms 30, with at least one edge defined by the first concreteslab 300 with the metallic dowels 80 extending therefrom. If anotherslab of concrete in addition to the one formed by the second enclosedarea 410 is desired, the forms 30 will again include one or more studs20 inserted thereon, and one or more covers 10 placed on the studs 20. Asecond slab of concrete 400 is poured into the second enclosed area 410,and is allowed to cure. In this fashion, a cold joint between the firstslab of concrete 300 and the second slab of concrete 400 is formed.

As illustrated in FIGS. 8 and 9, the exposed metallic dowels 80 isembedded within the second slab of concrete 400, and extends into thefirst slab of concrete 300 via the speed cover 10. With steel havingsubstantially the same coefficient of thermal expansion as concrete,during temperature shifts the first slab of concrete 300 is permitted toexpand and contract about the second slab of concrete 400 and vice versaalong axis X of the metallic dowel 80. Further, the aforementionedmolded plastic construction of the speed cover 10 enable the first andthe second concrete slabs 300 and 400, respectively, to expand andcontract a limited amount along the Z and Y axes. As a person ofordinary skill in the art will recognize, however, metallic dowel 80 isconfigured to significantly reduce such transformations. Thus, while theflexible characteristics of the speed cover 10 enable minisculeadjustments, large expansions and contractions are diminished by theplacement of the metallic dowel 80.

The particulars shown herein are by way of example and for purposes ofillustrative discussion of the embodiments of the present invention onlyand are presented in the cause of providing what is believed to be themost useful and readily understood description of the principles andconceptual aspects of the present invention. In this regard, no attemptis made to show structural details of the present invention in moredetail than is necessary for the fundamental understanding of thepresent invention, the description taken with the drawings makingapparent to those skilled in the art how the several forms of thepresent invention may be embodied in practice.

1. A concrete dowel placement device for attachment to a form,comprising: a stud having a generally tubular body, a proximal stud endand a distal stud end; and a cover having a generally tubular bodyhaving an outer cover surface, an open proximal cover end, a closeddistal cover end, and a hollow cover interior compartment extendingaxially therein configured to slidably receive said stud. 2-17.(canceled)